In my experience electrical tape has been a problem often enough that I
prefer not to use it. If you're bundling and positioning the loom, use
zip ties. If you're insulating it and protecting it from abuse, use
maybe a short length of tape over damaged insulation, inside a length of
split loom sleeve. Otherwise I fear you'll discover dangling tape and
damaged loom a few years hence.
On my Prestolite EV motor all the screws threaded into the housing are
tri-lobed self tapping screws. My guess is that the best material
magnetically is pretty soft mechanically, so they just drill pilot holes
in production and drive in self-tappers as a cost savings. If that is
true on your motor, machine screws likely won't work and trying to use
them could strip out the soft metal. Hunt around the motor and see if
any of the other screws have a slightly tri-lobed shape to them, or if
they're some other form of self tapping screw. You want to get a good
match here.